Electrical heating device.



G. A. HUGHES. ELFIJTRCAL HEATING DEVICE. Awmm'wm NLE JULY u, 1912.

Patented July 29, 1913.

2 SHEETS-SHEET L G. A. HUGHES.

ELECTRICAL HEATING DBVIGE.

APPLICATION FILED JULY 11,1912

1,068,658. Patented July 29, 1913.

2 SHEETSSHEET 2v .CMM f W 1 siderable attention members, owing toexpansion and contrac- UNITED STATES PATENT. OFFICE.

GEORGE A. HUGHES, 0F CHICAGO, ILLINOIS, ASSIGNOR TO HUGHES ELECTRICHEATING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

ELECTRICAL HEATING DEVICE.

To all '1o/1,0m @'15 may concern.'

Be it loiown that I, GEORGE A. HUGHES, a resident of "Chicago, county ofCook, and State of Illinois, have invented certain new and usefulImprovements in Electrical HeatingDevices, of which the following isspec-icatiol.V

Myfinvention relates to electrical heating devices and contemplatesvarious improvements iny` construction and arrangement. My inventionconcerns particularly heating devices in which heating units areprovided with heating conductor sections adapted fdr connection inelectrical curcuits.

In the co-pending application of myself and Trevor M. Caven, Serial No.566,298, is shown an arrangement in which a heating unit has appliedthereto a plurality of lengths of heating conductors or spirals, eachconductor at its end being secured by means of terminal bolts, and thesebolts are connected on the back of the supporting plate and contactterminals are provided for connection with terminal sockets provided inthe supporting base. In such constructions where a lgreat number ofmetallic fastening and terminal members are provided conis required, asthese tion under great temperature variations soon loosen up and causeimperfect contacts or open e-ircuits. The manufacture of such unitsinvolving separate heating conductors rand many terminal membersrequires considerable time and is quite expensive.

One of the importantI objects of my invention is therefore to provideconstruction and arrangement for overcoming such undesirable featuresand which will greatly decrease the cost of manufacture and maintenanceand which, will greatly increase the eiliciency. Instead of having aplurality of such heating conductors, I provide a pluralityof heatingconductors sections by applying to a suitable plate a continuous heatingconductor br spiral and I securely anchor the end of the heat-ingsections to the plate without the use of separate bolts,

screws, or other fastening or terminal means.`

A number of such heating conductors or spirals, preferably two, areapplied so that various connections with the electrical cir- Speccationof Letters Patent. Application .filed July 11, 1912.

'minal bolts 15 and Patented July 29, 1913. serial No. 708,847.

cuit may be made to produce varying del grecs of heat.

Another object of the invention is to provide terminals for the unitoutside of the intense heat zone so that connections with a supplycircuit can be more readily made. he unit is placed in a supportingblock and main terminal conductors extend therefrom through openings insaid supporting block to connect with terminals mounted at the outsideof the block and well away from the heat of the unit. At the same timear'- iangement is made so that upon disconnection of the unit terminalsfrom the supply circuit terminals the unit can be readily lifted fromits supporting block for inspection or repairs. l

The various features of my invention are clearly shown on theaccompanying draw-, ings in which* Figure l is a plan view of the unit,Fig. 2 is an end view, Fig. 3 is a sectional View taken on plane 3-3Fig. l, Fig. 4 is av sectional view taken on plane 4-4 Fig. 1, Fig. 5 isa View of the bottoinof the unit, and Fig. 6 is a sectional view takenon plan (l--G Fig. 1 and showing in addition and in section thesupporting block fr the unit.

The unit comprises a plate 10 of refractory material preferably of highheat conductivity, this plate having a plurality of parallel ridges 11extending upwardly to provide the'parallel grooves 12 'for receiving theheating conductor sections. Thea unit may be of lany desired contour.The y unit shown is 'rectangular and arrangedI for receiving twocontinuous heat producing conductors to form a multiplicity of heatconductor sections. At one corner the plate has two holes 13 and 14 forreceiving ter- 16 whose nuts engage at the under side of the`= plate tosecure thereto the end of the heating conductor lengths 17 and 18. Thesebolts are at the ends of the end grooves 12a and l2b and immediatelyadjacent thereto bolt holes 19 and 2O are provided through which the theheating conductor lengths pass forengagement with the terminal bolts vatthe under side of the plate. At the opposite ends of the grooves 12h1and 12b holes 21 and 22 are provided, hole 2l being the edge of theplate and hole 22 b ends of adjacent A of grooves 12C and 12d have attheir en ds distance inward therefrom. The second set holes 19C, 19d,and 21, 22C. At tliefopposite corner of the plate the grooves 12x and12y have the holes 23 and 24 for receiving the terminal bolts 25 and 26for receiving at the lower side of the plate the other terminals of theheating conductor lengths 17 and 18. lini'nediately in front. of theseholes are the hol-es 27 and 28 through which the ends of theseconductors pass from the top of the plate. The first groove 12n andalternate grooves thereafter are serially connected together at theirends by the holes at the ends of said grooves and grooves 29` iii thebottom of the block. As shown, the upper end of the first groove 12communi cates through hole 2l, groove-@Sand hole 21c with the top of thethird groove, and the lower end of this third groove communicatesthrough hole 19C, groove 29 and hole 192 with the lower end of the fifthgroove, and so on, so that a continuous groove is formed for the heatingconductor length 17 from its terminal 15 to the terminal 25. In likemanner the ends of the second, fourth, sixth, etc., grooves on the faceof the plate are connected together by cross grooves to form asubstantially continuous groove for conductor 18 from its terminal 16 toterminal 26. In order that these cross grooves will not interfere, theend holes of the even number grooves are offset longitudinally from theholes of the odd inimber grooves, as is plainly indicated. i

When a plate is formed the one set of ends of the conductor lengths 17and 18 is in sert-ed through holes 19 and 20 and secured at the bottomof the plate to the terminal bolts 15 and 16. The respective conductorsare then laid in the first set of grooves 12 and 12b, then passedthrough the holes 21 and 22 and through the corresponding cross grooves29a and 29b to the holes 21c and 22"', thence upwardly through theseholes and in the grooves 12 and 12d then are again passed to the bottomof the plate 'through holes 19c and 19d and through the corre! spendingcross Agrooves and holes to the .tace of the plate and in the fifth andsixth grooves, and so on until the other ends of the conductor lengthsare passed down; wardly through holes 27 and 2S and conhected with theterminal bolts 25 and 26 at the opposite corner ofthe plate. Theconductor lengths are thus securely anchored at their bends to the plateand are entirely t protected in the longitudinal grooves and crossgrooves Without the necessity of any The conductor length are preferablyin the vform of continuous spirals of high resistance wire s l i l l land after application of these lengths to the l plate as fust described,the various heating sections are securely held on the face of the. blockin the longitudinal grooves or channels and protected by the ridges 11.

The terminal screws 15, 16 and 25, 26 may be connected directly withcurrent supply conductors of which a preferred ar-v rangement is asshown'in Figs.- 5 and 6 Along the central longitudinal line of the plateholes 30, 31 and 32 are provided for receiving terminal screws 33, 34and 35, and on the bottom of the plate these terminal screws areconnected by suitable current conductors with the heating sectionterminals. As shown, the conductor 36 connects terminal screw with screw26 and a conductor 37 connects terminal screw 33 with screw 25, whilethe conductor 38 connects terminal screw with both terminal screws 15and 16 on the. heat-ing sections.

Referriir'to Fig. G each heating plate is supported block 39, having arectangular pocket 40 whose opposite walls have supporting ledges 41'forreceiving the plate, the plate when applied having the upper ends of itsridges 11 substantially flush with the top surface of the supportingblock and having its lower surface separated by the air space 42 fromthe base 43 of the block. Along the central longitudinal line of thisbase, holes 44 are provided to register with the terminal screws 34 and35 ofthe plate and adjacent each of the holes 44 a terminal bracket 45is secured in the under side of the block, and each bracket carries a`binding screw 4G for connection by a con- .ductor 47 with thecorresponding terminal `1screw on the plate. lVhen the plate is appliedto the block these conductors 47 pass through the holes 44 and aresecured to the various terminal brackets, and upon withdrawal of bindingscrews 4G the plate with conductors 47 can be readily removed from theblock. The terminal brackets may con- 'nectthrough suitable switchmechanism with the current supply conductors so that various heatingcombinations may be adjusted for, as for example, serial inclusion ofboth the heating conductor lengths 17 and 18, or parallel inclusion ofsuch conductors in circuit, or inclusion of only one thereof in,circuit- As the supporting block is of material highly uon-conductive toheat the terminal brackets are protected from the intense heat adjacentthe plate and are vkept comparatively cool so tliat'the circuitconnections can be readily made or changed at any time, or disconnectionof the plate effected. l

instead of having the plate of rectangular contour it can be ofdifferent contour. lt might be circular and the heating con doctorlengths applied thereto in spirlarangement and looped through suitableholes at intervals so that the heating conductor sections willbesecurely held in place on tlie plate. Other' modifications might alsobe possible which will still @eine withY l bination of a plate ofrefractory materialA said plate having pairs or nales there Z through atintervals, and a, resistance vm.-

ductor arranged on the fare :if said plaie i and looping through theholes o' each pair.

lnm'iifg;

.said plate connenting the holes of with pair u there being grooves inthe under siir of and receiving said conductor.

2. In an electrical heating unit. the nu bination of a plate ofrefractory material hs are full protected threiiwl'miit their i havingparallel channels in its fave and` holes at the 'end of earh Channel :itthe haelt' i of the plate, and a continuelle rigaaislziiwe f v conductorapplied in said rhannels :wel

Liz-amiral with the aim inl mui-ml to said al-Neal lifting' rhinite, thei plaie haring a plurality of longitudine? allarmi in 'laffe and mehgroow inning' "wmwwi ai i-avh end vwilli ilu: luuk the g-Wtalay :ipassageway.

4 l "'wr extending ,-i an'l piu-sagt lliaial Channels lillvmziliiimlioii Yt ils XX V'l V61 in ll i i rg/wed between :liv com fiilel'lerial i i-lianiiels ille ifiils of aid channel 'lililtl'ziiirsi'ebfe Lil plate winiieett l'oi'niiiig with '@nlaiiioiisviralimlng serially l. a plurallooping through said holes` to the. hall;el iiwefl he the plate, adjacent holes living conm/ered lijf l #hannesein-h grooves iii the back oi' the plaie ier rwf'ai f hai ing holes fix.

ing the continuous poeliet. and a minimali@ heating eornlurtor appliedin irl i l 4. ln an eleetrieal heat-ing unit.. the Hi binatio-n of abase of insulating mmfsaid plate having in its ta're a pliii'aitlongitudinal grooves and each ginm-fhf ing Connected at each end hy :ipassageway with the back of the plate, transvlfi'sely tending-grooves inthe hack of sail plate connecting with adjacent passageways. saidchannels, passageways and groei farming the continuous pocket` und aCeiitinueiie heating conductor applied in snrl pin-lai.

vii te, transversely wel( of siiifl plate unil Niles rif tlii? i eating'said Mater-l hel-ils mieli ot' said L the coinr material upper face, l'riwilrowffli and

